EXPRESS: Testis torsion in a non-neoplastic cryptorchid testis of a cat

Case Summary Cryptorchidism is a condition rarely encountered in cats with a reported prevalence below 3.8%. In the canine species it is known to predispose for both testicular torsion and neoplasia, therefore cryptorchidectomy is recommended. While neoplasia was previously described in feline cryptorchid testes, testicular torsion is a very rare condition in cats. This is the first description of a testicular torsion in a non-neoplastic, abdominal testis of a tomcat. A 1-year-old male domestic longhair cat was admitted for elective orchidectomy. Physical examination revealed right unilateral cryptorchidism. The testis could be located within the abdomen upon ultrasonographic examination. Cryptorchidectomy and scrotal orchidectomy of the contralateral testis were performed. The abdominal testis appeared severely discoloured to a dark blue colour and the spermatic cord was twisted. The scrotal testis appeared normal. Surgery and post-surgical recovery were uneventful. Histopathological examination of the abdominal testis revealed a severe, diffuse congestion with significant interstitial haemorrhage and oedema in both the testis and epididymis. Spermatogenesis showed arrest on the level of spermatogonia and Sertoli-cell-only syndrome, which is commonly encountered in abdominal cryptorchid testes. Relevant and novel information The presented case shows that testicular torsion is a possible complication of cryptorchidism in cats. Thus, prevention of such torsion can be seen as an additional indication for cryptorchidectomy besides the previously reported increased risk of neoplasia and the common reasons for neutering of tomcats, such as population control and elimination of unwanted male behaviour.